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Small Grains Weed Control in
Small Grain Crops


Several weeds cause problems in wheat production. The most serious weeds are wild garlic and wild onion, mainly wild garlic. Vetch and wild winter peas also are problems, especially if you are producing the grain for seed. Vetch seed are difficult to remove in cleaning. Other broadleaf weeds (dock, wild turnip, wild radish, wild mustard, and buttercup) sometimes are troublesome. Occasionally, warm-season grasses and broadleafs are a problem in some instances and can greatly reduce grain yields and cause harvesting problems.

Crop, weed, or
situation and active
chemical per treated
land acre		 Formulation needed
to treat 1 acre
broadcast		 Time of
application		 Weeds
controlled		 Special instructions and remarks
Preemergence -- Wheat
diclofop methyl at 0.75 to 1.0 lb/A 2.0 to 2.67 pt of Hoelon 3 EC in at least 10 gal water for ground and 5 gal water for air. After seeding. Annual ryegrass. Do not apply preemergence to other small grains. In coarse-textured soils with less than 2% organic matter use the low rate. Use the higher rate for fine-textured soils with more than 2% organic matter. Use high rate if ryegrass pressure is heavy no matter what the soil type or organic matter is. See postemergence Hoelon for wheat information in the next page for additional restrictions.
Postemergence -- Oats, wheat, rye, and barley
2,4-D at 1.0 lb/A 2,4-D amine salts or 2,4-D low-volatile ester. Use 1 qt (4 lb/gal formulation) in 5 to 10 gal water for air and in 10 to 20 gal of water for ground application. Add 1 pt surfactant for each 50 gal of spray mix. During warm sunny weather immediately after winter dormancy and before grain begins to joint. In most years, this period occurs in February. Most broadleaf weeds and suppression of wild garlic and/or onions. Use the low-volatile ester formulation where wild garlic and/or onions are a problem. Follow label precautions carefully. When applied with liquid nitrogen, use 0.5 quart per acre. Mix low-volatile ester directly; dilute amine form with 3 to 5 parts water before mixing.
dicamba + 2,4-D at 0.125 + o.50 lb/A Banvel SGF -- 0.5 pt plus 1.0 pt (4 lb/gal formulation) of 2,4-D amine or low-volatile ester in 5 gal water for air and in 10 to 20 gal water for ground application. Add 1 pt surfactant for each 50 gal spray mix. Same as above Same as above. Garlic and/or onions. Same as above. The low-volatile ester formulation should be used where wild garlic and/or onions are a problem. See label for injury precautions.
Postemergence -- Wheat
diclofop methyl at 0.5 to 1.0 lb/A 1.33 to 2.67 pt Hoelon 3EC in at least 10 gal water and a minimum of 40 psi for ground; 5 gal water by air. Surfactant not needed. When ryegrass is in the 1- to 2- tiller stage. Annual ryegrass. If ryegrass is in the 5-leaf to 2-tiller stage use high rate. Do not mix with other pesticides or liquid fertilizer. Do not graze treated fields or feed treated forage to livestock. Broadleaf herbicides should not be applied within one week of Hoelon application. Do not make more than 1 application per season. Activity is slow. Do not make aerial application when win is above 5 mph or within 100 feet of lake, pond, stream, drainage basin, or tidal marsh.
Postemergence -- Wheat and Oats
thifensulfuron + thribenuron at 0.104 to 0.028 lb/A Harmony Extra 75DF - 0.3 to 0.6 oz in 2 to 5 gal water for air and in 10 to 20 gal water for ground application. Add 1 pt surfactant for each 50 gal spray mix. Do not exceed 0.4 oz on oats. When wheat and oats are 2-leaf but before "boot stage." Garlic, curly dock, winter annual broadleafs. Apply to provide excellent coverage of weeds. Several hours of dry weather are needed to allow absorption by foliage. Garlic should be treated in spring when actively growing. Do not mix with Hoelon. Application with liquid nitrogen may increase crop injury. Do not harvest sooner than 45 days after the last application
Preharvest -- Wheat
glyphosate 0.37 to 0.75 lb/A Roundup Ultra - 16 to 32 oz/A in 3 to 10 gal water by air or in 10 to 20 gal water by ground. After wheat has 30% or less moisture and at least 7 days before harvest. Annual broadleaf and grass weeds, johnsongrass, marestail. Do not use on wheat grown for seed. Avoid drift to nearby crops that are not Roundup resistant.


Stages when wheat injury occurs with 2,4-D
By Dr. D. Wayne Houston, revised by John Byrd, Ph.D., Extension Weed Specialist.

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Publication 1344

Extension Service of Mississippi State University, cooperating with U.S. Department of Agriculture. Published in furtherance of Acts of Congress, May 8 and June 30, 1914. Ronald A. Brown, Director

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